1. Technical Field
The present invention relates primarily to the cleaning of pipes, and more particularly, to an apparatus and method for electropolishing the inner surface of pipes and metallic tubing.
2. Description of the Prior Art
Today many industries require 100% pure constituents for processes and manufacturing operations, such as in the production of computer chips. In particular, transistor densities on computer chips can reach thousands of devices per square inch, which means even minute amounts of impurities in the constituents can destroy a computer chip under production. One significant source of impurities is often the piping or tubing used to transport constituents during the manufacturing operations. Such tubing is typically made of metallic compounds, which may harbor numerous different types of impurities: such as oxides, metal flakes, dirt, etc. A demand therefore exists for tubing having a highly polished contaminant free inner surface.
Existing methods for cleaning the inner surface area of metallic tubing include flushing and brushing, both of which are labor intensive, requiring significant time and personalized attention to the workpiece. Furthermore, such techniques often result in an inadequate cleaning, especially if the tubing is configured with one or more bends. Bending metallic tubing not only makes brushing and flushing physically more difficult but bending actually generates impurities by creating wrinkles and small flakes in the metal on the inner surface of the workpiece.
As described herein, the present inventive technique utilizes a special electropolishing process to clean the inside of metallic tubing. One system/method for electropolishing pipes is disclosed in U.S. Pat. No. 4,882,019 by Lewy, entitled "Apparatus and Method for Polishing a Plumbing or Electrical Fixture." Briefly, this patent describes the electropolishing of plumbing fixtures for improved solder jointing. In particular, the patent addresses cleaning the outside of a copper pipe and the first several inches of the inside of the pipe to facilitate soldering of the pipes. By way of example, the technique described is particularly useful for facilitating the soldering of pipes within a residential dwelling.
In contrast, the metallic tubing used in many manufacturing processes (e.g., in the manufacture of computer chips) can be 1/8" in diameter and 10' in length. The cleaning of the inner surface area of such tubing creates unique problems which have yet to be adequately addressed. Thus, an improved approach to quickly and efficiently clean the inner surface of tubing shaped in any of various configurations is believed to be commercially significant.